Add select-all, deselect-all and invert-selection options to filters

To every filter list add a menu button that allows selection of all,
selection of none or inversion of selection.

Implements #435.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

desktop-widgets/listfilter.ui

@@ -51,6 +51,16 @@
        </property>
       </widget>
      </item>
+     <item>
+      <widget class="QToolButton" name="selectionButton">
+       <property name="text">
+        <string>...</string>
+       </property>
+       <property name="popupMode">
+        <enum>QToolButton::InstantPopup</enum>
+       </property>
+      </widget>
+     </item>
     </layout>
    </item>
    <item>

desktop-widgets/simplewidgets.cpp

@@ -513,6 +513,12 @@ FilterBase::FilterBase(FilterModelBase *model_, QWidget *parent)
 	filter->setFilterCaseSensitivity(Qt::CaseInsensitive);
 	connect(ui.filterInternalList, SIGNAL(textChanged(QString)), filter, SLOT(setFilterFixedString(QString)));
 	ui.filterList->setModel(filter);
+
+	QMenu *menu = new QMenu(this);
+	menu->addAction(tr("Select All"), model, &FilterModelBase::selectAll);
+	menu->addAction(tr("Unselect All"), model, &FilterModelBase::clearFilter);
+	menu->addAction(tr("Invert Selection"), model, &FilterModelBase::invertSelection);
+	ui.selectionButton->setMenu(menu);
 }
 
 void FilterBase::showEvent(QShowEvent *event)

qt-models/filtermodels.cpp

@@ -100,6 +100,21 @@ void FilterModelBase::clearFilter()
 	emit dataChanged(createIndex(0,0), createIndex(rowCount()-1, 0));
 }
 
+void FilterModelBase::selectAll()
+{
+	std::fill(checkState.begin(), checkState.end(), true);
+	anyChecked = true;
+	emit dataChanged(createIndex(0,0), createIndex(rowCount()-1, 0));
+}
+
+void FilterModelBase::invertSelection()
+{
+	for (char &b: checkState)
+		b = !b;
+	anyChecked = std::any_of(checkState.begin(), checkState.end(), [](char b){return !!b;});
+	emit dataChanged(createIndex(0,0), createIndex(rowCount()-1, 0));
+}
+
 SuitsFilterModel::SuitsFilterModel(QObject *parent) : FilterModelBase(parent)
 {
 }

qt-models/filtermodels.h

@@ -11,6 +11,8 @@ class FilterModelBase : public QStringListModel {
 public:
 	virtual bool doFilter(struct dive *d, QModelIndex &index0, QAbstractItemModel *sourceModel) const = 0;
 	void clearFilter();
+	void selectAll();
+	void invertSelection();
 	std::vector<char> checkState;
 	bool anyChecked;
 protected: